WB, I  don’t have mining experience to comment on this particular flow chart, I remember someone on this board has and comment before. 

But I did work with HF ,hydrofluoric acid is very similar what LAC facility will use for leaching process. From my experience it is very deadly acid and numerous fatalities occurred in Australia , India , etc if proper safety technics are not observed.  Our safety protocol was very strict and top of the line scrubbers and alarm systems were used.

OSHA keeps very close eye on this type of process. And any unahorised release  into atmosphere will result in strict penalties follow with warning of shutting down facility all together. I was personally involved in a safety in our process and fully understand benefits and danger working with such acids. I just hope LAC management will take this process very seriously for their and  all of us sake.